The present invention relates generally to the field of articulated bed frames.
It has been generally known heretofore from a number of known arrangements to provide sofa-bed structures in which pivotally connected bed sections could be selectively actuated into an extended bed-forming position or into a sofa seat-forming position. Exemplary of these constructions is the arrangement disclosed in the Spitz, et al U.S. Pat. No. 3,868,733 which discloses a plurality of frame sections, including a foot section, knee section, trunk section and head section pivoted in end-to-end relation, the trunk section being supported upon forward and rearward support assemblies, and the head section being operatively connected through a linkage mechanism such that during folding and unfolding operations of the bed frame, the head section will be moved so as to occupy a substantially horizontal position when the bed frame sections are in a bed-forming position, and a substantially vertical position when the bed frame sections are moved into a sofa seat-forming position.
Characteristic of the foregoing embodiments is the utilization of a front guiding link assembly for the trunk section which is pivotally connected with the upper end of a front upstanding anchor link having its lower end pivoted at a front pivot point on a stationary anchor frame plate. A rear guiding link assembly for the trunk section is also pivotally connected with the upper end of an upstanding fixed rear bracket attached to and extending above a rear end portion of the stationary anchor frame plate.
Other patents have also been known, as exemplified by the disclosure in the Mikos U.S. Pat. No. 3,516,096 in which pivoted front and rear support links are interconnected by a control link on the same side of the respective bottom pivots of the front and rear support links. This control link in effect ties the support links together so that they are operatively maintained in substantially parallel relation and so that their pivotal movements will always be in the same direction.
Another known concept for the mounting of pivotally swingable front and rear support links or levers is that exemplified by the arrangement disclosed in the Mikos U.S. Pat. No. 4,253,205 in which the rear support lever means has a movable supporting pivot, and the control link means, which are connected between the front and rear support lever means are operable to control the movement of the rear support lever means as the bed frame is moved between extended and retracted positions. In the disclosed arrangement, two control links are utilized. One link interconnects the front and rear support levers in a manner similar to that disclosed in the above mentioned U.S. Pat. No. 3,516,096 while the other link is connected to the movable supporting pivot of the rear support lever and acts to movably shift its position forwardly and rearwardly along a horizontal slot in the mounting frame member.
From a careful consideration of the best known linkage mechanisms in the folding bed-sofa art, and in particular the arrangements disclosed in the patents as previously noted above, it became apparent that the currently known structures could advantageously be improved in a number of areas, and in particular that such improvements should preferably include the following objectives:
A. To increase the floor clearance of the frame sections during their articulated folding and unfolding movements; PA1 B. To lower the rear portion of the closed bed frame in relation to the floor; and PA1 C. To dispose the extended open bed frame at a more desirable position forward of the associated upholstered back-rest, and at a more desirable height above the floor. PA1 1. The length of the open bed can be increased, while at the same time retaining the articulated movements of the mechanism within the restricted and confined dimensions dictated by the associated furniture frame structure. PA1 2. The depth of the space provided within the folded frame structure for the folded mattress can be increased, while at the same time retaining a relatively low seat level with the desired rake or pitch.
By achieving these objectives, two improved new product features are susceptible of attainment, namely:
In the present invention, these objectives and product features are made possible by the provision of unique coacting front and rear pivoted anchor links for controlling movements of the articulated bed frame sections during the folding and unfolding operations. For such purpose, the front anchor link is pivoted at its inner end at a front pivot point on an anchor frame plate. The rear anchor link comprises a rocker lever which is pivoted between its inner and outer ends at a rear pivot point on the anchor frame plate. A control link coordinates the movement of the front and rear anchor links, this control link being connected at one end to the front anchor link at a point adjacent its mounting pivot, and at its other end to the end of the rear anchor link that extends below its mounting pivot. As thus arranged, movement of the front anchor link, during movement of the frame sections between their fully folded and fully unfolded positions will cause the rear anchor link to successively move in one direction to carry the connected frame sections from a relatively lower elevation to an increased elevation, and then by a reversed direction of movement return the frame sections again to a relatively lower elevation.
In a further modification, greater bed length is obtainable over that just previously described by a unique arrangement in which the length of the head section is increased by fabricating it into two pivotally interconnected sections which combine to provide a head section of greater length than is possible with the previously described single section head section.
In the modified form, the two sections are articulated for controlled translatory movement between an extended unfolded bed-forming position in which the sections are in coplanar relation, and a folded retracted seat-forming position during which the two sections of the head sections assume a limited angular relationship that enables their accomodation within the confining cavity along the back of the sofa frame structure.